Refrigerant suction line filter/filter-drier and method for the

Abstract

A combined filter and filter-drier, for the suction side of refrigeration and air conditioning systems, comprises a dual filter system straddling a cylindrical plug of dessicant. Upstream of the dessicant, a rigidly built primary filter assembly comprises an inlet deflector and a stepped filter. Downstream of the dessicant, a secondary filter assembly comprises an outlet filter pad which is compressed by a coaxially disposed spring near the inlet of the filter/filter-drier. The inlet deflector is preferably triangular in shape and is disposed transversely to the inlet. The stepped filter comprises a deflector filter pad, which preferably has the same shape but a smaller size than the inlet deflector, and a filter pad which is round, preferably is twice as thick as the deflector filter pad, and has a smaller diameter than the inside diameter of the filter/filter-drier, whereby an annular space is provided for swirling flow of an incoming vaporous mixture which thereby enters the peripheries of the stepped filter. In consequence, particles are gradually deposited throughout the interiors of the deflector filter pad and inlet filter pad so that pressure build up across the filter/filter-drier is also gradual and provides a warning of impending need for replacement. A method for constructing the filter-drier is also disclosed.